mlxsw: spectrum: Handle NETDEV_CHANGE on L3 tunnels

Changes to L3 tunnel netdevices (through `ip tunnel change' as well as
`ip link set') lead to NETDEV_CHANGE being generated on the tunnel
device. Because what is relevant for the tunnel in question depends on
the tunnel type, handling of the event is dispatched to the IPIP module
through a newly-added interface mlxsw_sp_ipip_ops.ol_netdev_change().

IPIP tunnels now remember the last set of tunnel parameters in struct
mlxsw_sp_ipip_entry.parms, and use it to figure out what exactly has
changed.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/spectrum_ipip.c

@@ -287,6 +287,72 @@ mlxsw_sp_ipip_ol_loopback_config_gre4(struct mlxsw_sp *mlxsw_sp,
 	};
 }
 
+static int
+mlxsw_sp_ipip_ol_netdev_change_gre4(struct mlxsw_sp *mlxsw_sp,
+				    struct mlxsw_sp_ipip_entry *ipip_entry,
+				    struct netlink_ext_ack *extack)
+{
+	union mlxsw_sp_l3addr old_saddr, new_saddr;
+	union mlxsw_sp_l3addr old_daddr, new_daddr;
+	struct ip_tunnel_parm new_parms;
+	bool update_tunnel = false;
+	bool update_decap = false;
+	bool update_nhs = false;
+	int err = 0;
+
+	new_parms = mlxsw_sp_ipip_netdev_parms(ipip_entry->ol_dev);
+
+	new_saddr = mlxsw_sp_ipip_parms_saddr(MLXSW_SP_L3_PROTO_IPV4,
+					      new_parms);
+	old_saddr = mlxsw_sp_ipip_parms_saddr(MLXSW_SP_L3_PROTO_IPV4,
+					      ipip_entry->parms);
+	new_daddr = mlxsw_sp_ipip_parms_daddr(MLXSW_SP_L3_PROTO_IPV4,
+					      new_parms);
+	old_daddr = mlxsw_sp_ipip_parms_daddr(MLXSW_SP_L3_PROTO_IPV4,
+					      ipip_entry->parms);
+
+	if (!mlxsw_sp_l3addr_eq(&new_saddr, &old_saddr)) {
+		u16 ul_tb_id = mlxsw_sp_ipip_dev_ul_tb_id(ipip_entry->ol_dev);
+
+		/* Since the local address has changed, if there is another
+		 * tunnel with a matching saddr, both need to be demoted.
+		 */
+		if (mlxsw_sp_ipip_demote_tunnel_by_saddr(mlxsw_sp,
+							 MLXSW_SP_L3_PROTO_IPV4,
+							 new_saddr, ul_tb_id,
+							 ipip_entry)) {
+			mlxsw_sp_ipip_entry_demote_tunnel(mlxsw_sp, ipip_entry);
+			return 0;
+		}
+
+		update_tunnel = true;
+	} else if (mlxsw_sp_ipip_parms_okey(ipip_entry->parms) !=
+		   mlxsw_sp_ipip_parms_okey(new_parms)) {
+		update_tunnel = true;
+	} else if (!mlxsw_sp_l3addr_eq(&new_daddr, &old_daddr)) {
+		update_nhs = true;
+	} else if (mlxsw_sp_ipip_parms_ikey(ipip_entry->parms) !=
+		   mlxsw_sp_ipip_parms_ikey(new_parms)) {
+		update_decap = true;
+	}
+
+	if (update_tunnel)
+		err = __mlxsw_sp_ipip_entry_update_tunnel(mlxsw_sp, ipip_entry,
+							  true, true, true,
+							  extack);
+	else if (update_nhs)
+		err = __mlxsw_sp_ipip_entry_update_tunnel(mlxsw_sp, ipip_entry,
+							  false, false, true,
+							  extack);
+	else if (update_decap)
+		err = __mlxsw_sp_ipip_entry_update_tunnel(mlxsw_sp, ipip_entry,
+							  false, false, false,
+							  extack);
+
+	ipip_entry->parms = new_parms;
+	return err;
+}
+
 static const struct mlxsw_sp_ipip_ops mlxsw_sp_ipip_gre4_ops = {
 	.dev_type = ARPHRD_IPGRE,
 	.ul_proto = MLXSW_SP_L3_PROTO_IPV4,
@@ -294,6 +360,7 @@ static const struct mlxsw_sp_ipip_ops mlxsw_sp_ipip_gre4_ops = {
 	.fib_entry_op = mlxsw_sp_ipip_fib_entry_op_gre4,
 	.can_offload = mlxsw_sp_ipip_can_offload_gre4,
 	.ol_loopback_config = mlxsw_sp_ipip_ol_loopback_config_gre4,
+	.ol_netdev_change = mlxsw_sp_ipip_ol_netdev_change_gre4,
 };
 
 const struct mlxsw_sp_ipip_ops *mlxsw_sp_ipip_ops_arr[] = {

drivers/net/ethernet/mellanox/mlxsw/spectrum_ipip.h

@@ -56,6 +56,7 @@ struct mlxsw_sp_ipip_entry {
 	struct mlxsw_sp_rif_ipip_lb *ol_lb;
 	struct mlxsw_sp_fib_entry *decap_fib_entry;
 	struct list_head ipip_list_node;
+	struct ip_tunnel_parm parms;
 };
 
 struct mlxsw_sp_ipip_ops {
@@ -78,6 +79,10 @@ struct mlxsw_sp_ipip_ops {
 			    struct mlxsw_sp_ipip_entry *ipip_entry,
 			    enum mlxsw_reg_ralue_op op,
 			    u32 tunnel_index);
+
+	int (*ol_netdev_change)(struct mlxsw_sp *mlxsw_sp,
+				struct mlxsw_sp_ipip_entry *ipip_entry,
+				struct netlink_ext_ack *extack);
 };
 
 extern const struct mlxsw_sp_ipip_ops *mlxsw_sp_ipip_ops_arr[];

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c

@@ -943,7 +943,7 @@ __mlxsw_sp_ipip_netdev_ul_dev_get(const struct net_device *ol_dev)
 	return __dev_get_by_index(net, tun->parms.link);
 }
 
-static u32 mlxsw_sp_ipip_dev_ul_tb_id(const struct net_device *ol_dev)
+u32 mlxsw_sp_ipip_dev_ul_tb_id(const struct net_device *ol_dev)
 {
 	struct net_device *d = __mlxsw_sp_ipip_netdev_ul_dev_get(ol_dev);
 
@@ -1002,6 +1002,7 @@ mlxsw_sp_ipip_entry_alloc(struct mlxsw_sp *mlxsw_sp,
 
 	ipip_entry->ipipt = ipipt;
 	ipip_entry->ol_dev = ol_dev;
+	ipip_entry->parms = mlxsw_sp_ipip_netdev_parms(ol_dev);
 
 	return ipip_entry;
 
@@ -1017,12 +1018,6 @@ mlxsw_sp_ipip_entry_dealloc(struct mlxsw_sp_ipip_entry *ipip_entry)
 	kfree(ipip_entry);
 }
 
-static bool mlxsw_sp_l3addr_eq(const union mlxsw_sp_l3addr *addr1,
-			       const union mlxsw_sp_l3addr *addr2)
-{
-	return !memcmp(addr1, addr2, sizeof(*addr1));
-}
-
 static bool
 mlxsw_sp_ipip_entry_saddr_matches(struct mlxsw_sp *mlxsw_sp,
 				  const enum mlxsw_sp_l3proto ul_proto,
@@ -1471,6 +1466,35 @@ mlxsw_sp_netdevice_ipip_ul_vrf_event(struct mlxsw_sp *mlxsw_sp,
 						   true, true, false, extack);
 }
 
+static int
+mlxsw_sp_netdevice_ipip_ol_change_event(struct mlxsw_sp *mlxsw_sp,
+					struct net_device *ol_dev,
+					struct netlink_ext_ack *extack)
+{
+	const struct mlxsw_sp_ipip_ops *ipip_ops;
+	struct mlxsw_sp_ipip_entry *ipip_entry;
+	int err;
+
+	ipip_entry = mlxsw_sp_ipip_entry_find_by_ol_dev(mlxsw_sp, ol_dev);
+	if (!ipip_entry)
+		/* A change might make a tunnel eligible for offloading, but
+		 * that is currently not implemented. What falls to slow path
+		 * stays there.
+		 */
+		return 0;
+
+	/* A change might make a tunnel not eligible for offloading. */
+	if (!mlxsw_sp_netdevice_ipip_can_offload(mlxsw_sp, ol_dev,
+						 ipip_entry->ipipt)) {
+		mlxsw_sp_ipip_entry_demote_tunnel(mlxsw_sp, ipip_entry);
+		return 0;
+	}
+
+	ipip_ops = mlxsw_sp->router->ipip_ops_arr[ipip_entry->ipipt];
+	err = ipip_ops->ol_netdev_change(mlxsw_sp, ipip_entry, extack);
+	return err;
+}
+
 void mlxsw_sp_ipip_entry_demote_tunnel(struct mlxsw_sp *mlxsw_sp,
 				       struct mlxsw_sp_ipip_entry *ipip_entry)
 {
@@ -1552,6 +1576,10 @@ int mlxsw_sp_netdevice_ipip_ol_event(struct mlxsw_sp *mlxsw_sp,
 								    ol_dev,
 								    extack);
 		return 0;
+	case NETDEV_CHANGE:
+		extack = info->extack;
+		return mlxsw_sp_netdevice_ipip_ol_change_event(mlxsw_sp,
+							       ol_dev, extack);
 	}
 	return 0;
 }

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.h

@@ -70,6 +70,7 @@ struct mlxsw_sp_rif *mlxsw_sp_rif_by_index(const struct mlxsw_sp *mlxsw_sp,
 u16 mlxsw_sp_rif_index(const struct mlxsw_sp_rif *rif);
 u16 mlxsw_sp_ipip_lb_rif_index(const struct mlxsw_sp_rif_ipip_lb *rif);
 u16 mlxsw_sp_ipip_lb_ul_vr_id(const struct mlxsw_sp_rif_ipip_lb *rif);
+u32 mlxsw_sp_ipip_dev_ul_tb_id(const struct net_device *ol_dev);
 int mlxsw_sp_rif_dev_ifindex(const struct mlxsw_sp_rif *rif);
 u8 mlxsw_sp_router_port(const struct mlxsw_sp *mlxsw_sp);
 const struct net_device *mlxsw_sp_rif_dev(const struct mlxsw_sp_rif *rif);
@@ -138,4 +139,10 @@ void mlxsw_sp_nexthop_counter_alloc(struct mlxsw_sp *mlxsw_sp,
 void mlxsw_sp_nexthop_counter_free(struct mlxsw_sp *mlxsw_sp,
 				   struct mlxsw_sp_nexthop *nh);
 
+static inline bool mlxsw_sp_l3addr_eq(const union mlxsw_sp_l3addr *addr1,
+				      const union mlxsw_sp_l3addr *addr2)
+{
+	return !memcmp(addr1, addr2, sizeof(*addr1));
+}
+
 #endif /* _MLXSW_ROUTER_H_*/